Batch and heel are two types of electric induction processes for heating and melting of electrically conductive materials. In the batch process, a crucible is filled with a batch of electrically conductive solid charge that is melted by electric induction and then emptied from the crucible. In the heel process, a molten heel (bottom pool) of electrically conductive material is always maintained in the crucible while solid electrically conductive charge is added to the heel in the crucible and then melted by electric induction. Inductively heating and melting by the heel process when the material is non-electrically conductive in the solid state and electrically conductive in the molten state (referred to as a transition material), such as silicon, is problematic in that addition of solid non-electrically conductive charge to the molten heel must be adequately melted and mixed so that the added solid charge does not accumulate to form aggregate non-electrically conductive solid masses in, or over, the surface of the molten material.
It is one object of the present invention to provide apparatus for, and method of, heating and melting of a material that is non-electrically conductive in the solid state and electrically conductive in the molten state in a heel electric induction heating and melting process.